lkml.org 
[lkml]   [2019]   [Dec]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v13 4/7] drm/sun4i: dsi: Handle bus clock via regmap_mmio_attach_clk
On Sat, Dec 21, 2019 at 05:11:00PM +0530, Jagan Teki wrote:
> On Thu, Dec 19, 2019 at 3:35 AM Maxime Ripard <mripard@kernel.org> wrote:
> >
> > On Thu, Dec 19, 2019 at 12:40:14AM +0530, Jagan Teki wrote:
> > > regmap has special API to enable the controller bus clock while
> > > initializing register space, and current driver is using
> > > devm_regmap_init_mmio_clk which require to specify bus
> > > clk_id argument as "bus"
> > >
> > > But, the usage of clocks are varies between different Allwinner
> > > DSI controllers. Clocking in A33 would need bus and mod clocks
> > > where as A64 would need only bus clock.
> > >
> > > Since A64 support only single bus clock, it is optional to
> > > specify the clock-names on the controller device tree node.
> > > So using NULL on clk_id would get the attached clock.
> > >
> > > To support clk_id as "bus" and "NULL" during clock enablement
> > > between controllers, this patch add generic code to handle
> > > the bus clock using regmap_mmio_attach_clk with associated
> > > regmap APIs.
> > >
> > > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > > ---
> > > Changes for v13:
> > > - update the changes since has_mod_clk is dropped in previous patch
> > >
> > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 45 +++++++++++++++++++++-----
> > > 1 file changed, 37 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > > index 68b88a3dc4c5..de8955fbeb00 100644
> > > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > > @@ -1081,6 +1081,7 @@ static const struct component_ops sun6i_dsi_ops = {
> > > static int sun6i_dsi_probe(struct platform_device *pdev)
> > > {
> > > struct device *dev = &pdev->dev;
> > > + const char *bus_clk_name = NULL;
> > > struct sun6i_dsi *dsi;
> > > struct resource *res;
> > > void __iomem *base;
> > > @@ -1094,6 +1095,10 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
> > > dsi->host.ops = &sun6i_dsi_host_ops;
> > > dsi->host.dev = dev;
> > >
> > > + if (of_device_is_compatible(dev->of_node,
> > > + "allwinner,sun6i-a31-mipi-dsi"))
> > > + bus_clk_name = "bus";
> > > +
> > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > base = devm_ioremap_resource(dev, res);
> > > if (IS_ERR(base)) {
> > > @@ -1107,25 +1112,36 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
> > > return PTR_ERR(dsi->regulator);
> > > }
> > >
> > > - dsi->regs = devm_regmap_init_mmio_clk(dev, "bus", base,
> > > - &sun6i_dsi_regmap_config);
> > > - if (IS_ERR(dsi->regs)) {
> > > - dev_err(dev, "Couldn't create the DSI encoder regmap\n");
> > > - return PTR_ERR(dsi->regs);
> > > - }
> > > -
> > > dsi->reset = devm_reset_control_get_shared(dev, NULL);
> > > if (IS_ERR(dsi->reset)) {
> > > dev_err(dev, "Couldn't get our reset line\n");
> > > return PTR_ERR(dsi->reset);
> > > }
> > >
> > > + dsi->regs = devm_regmap_init_mmio(dev, base, &sun6i_dsi_regmap_config);
> > > + if (IS_ERR(dsi->regs)) {
> > > + dev_err(dev, "Couldn't init regmap\n");
> > > + return PTR_ERR(dsi->regs);
> > > + }
> > > +
> > > + dsi->bus_clk = devm_clk_get(dev, bus_clk_name);
> > > + if (IS_ERR(dsi->bus_clk)) {
> > > + dev_err(dev, "Couldn't get the DSI bus clock\n");
> > > + ret = PTR_ERR(dsi->bus_clk);
> > > + goto err_regmap;
> > > + } else {
> > > + ret = regmap_mmio_attach_clk(dsi->regs, dsi->bus_clk);
> > > + if (ret)
> > > + goto err_bus_clk;
> > > + }
> > > +
> > > if (of_device_is_compatible(dev->of_node,
> > > "allwinner,sun6i-a31-mipi-dsi")) {
> > > dsi->mod_clk = devm_clk_get(dev, "mod");
> > > if (IS_ERR(dsi->mod_clk)) {
> > > dev_err(dev, "Couldn't get the DSI mod clock\n");
> > > - return PTR_ERR(dsi->mod_clk);
> > > + ret = PTR_ERR(dsi->mod_clk);
> > > + goto err_attach_clk;
> > > }
> > > }
> > >
> > > @@ -1164,6 +1180,14 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
> > > pm_runtime_disable(dev);
> > > err_unprotect_clk:
> > > clk_rate_exclusive_put(dsi->mod_clk);
> > > +err_attach_clk:
> > > + if (!IS_ERR(dsi->bus_clk))
> > > + regmap_mmio_detach_clk(dsi->regs);
> > > +err_bus_clk:
> > > + if (!IS_ERR(dsi->bus_clk))
> > > + clk_put(dsi->bus_clk);
> >
> > You still have an unbalanced clk_get / clk_put here
>
> You mean it is not needed right since devm_clk_get has release call
> via devres_alloc?

Yes
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2019-12-21 17:03    [W:0.042 / U:8.408 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site